Another Qantas plane has been grounded due to safety issues, this time at Melbourne Airport after the plane's windshield started to crack.

The small cracks appeared in the plane's side windshield as it was flying between Los Angeles and Melbourne.

The jet was able to land safely but has been grounded to undergo repair work.

Qantas spokesman David Epstein says the crack did not pose a major safety threat to passengers and has since been replaced.

He says some passengers will face delays as the aircraft will not be able to depart until later tonight.

"We apologise to those passengers concerned," he said.

"We're attempting to rebook those passengers who are on connecting flights onto new connecting flights and we're providing hotel rooms [to] those people who require accommodation in Melbourne while they're waiting."

It is the second time this year that a Qantas flight has been grounded due to a cracked windshield.

The incident follows the grounding of a Boeing 747 on Friday due to fly from Brisbane to Los Angeles because of a wiring fault.

The same plane landed safely in Sydney last Tuesday after reporting engine problems about 30 minutes into a flight to Singapore.

Last Wednesday, the tyres of an A380 flying from London via Singapore burst on landing at Sydney Airport.